Abstract: In an aspect of the disclosure, a cutting tool includes a base member and a coating layer located on a surface of the base member. The coating layer includes a lower layer, an upper layer, and an intermediate layer located between the lower layer and the upper layer. The intermediate layer includes a first layer, a second layer, and a third layer. The first layer contains TiCx1Ny1Oz1 (0?x1<1, 0?y1<1, 0<z1<1, and x1+y1+z1=1). The second layer contains TiCx2Ny2Oz2 (0?x2<1, 0?y2<1, 0<z2<1, and x2+y2+z2=1). The third layer is located between the first layer and the second layer, and contains TiCx3Ny3Oz3 (0?x3<1, 0?y3<1, 0?z3<1, and x3+y3+z3=1). Here, z1>z3 and z2>z3.

Abstract: A cutting insert may include a base member and a coating layer. The base member may include a first and second surface. The coating layer may be located on the base member. The coating layer may include a first layer containing ?-aluminum oxide, which is located above the first surface and the second surface. The first layer may include a first region located above the first surface, and a second region located above the second surface. When an angle formed by a normal line of a crystal plane (001) of the ?-aluminum oxide in the first layer and a normal line of the surface of the base member is a first inclination angle, a peak of a distribution of the first inclination angle in the first region is located at a lower angle side than a peak of a distribution of the first inclination angle in the second region.

Abstract: In an aspect of the disclosure, a cutting tool includes a base member and a coating layer located on a surface of the base member. The coating layer includes a lower layer, an upper layer, and an intermediate layer located between the lower layer and the upper layer. The intermediate layer includes a first layer, a second layer, and a third layer. The first layer contains TiCx1Ny1Oz1 (0?x1<1, 0?y1<1, 0<z1<1, and x1+1+z1=1). The second layer contains TiCx2Ny2Oz2 (0?x2<1, 0?y2<1, 0<z2<1, and x2+y2+z2=1). The third layer is located between the first layer and the second layer, and contains TiCx3Ny3Oz3 (0?x3<1, 0?y3<1, 0?z3<1, and x3+y3+z3=1). Here, z1>z3 and z2>z3.